97-04-12: Compressor Bleed-off Valve

97-04-12 Pratt & Whitney Canada: Amendment 39-9936. Docket 97-ANE-01. Applicability: Pratt & Whitney Canada (PWC) PT6 series turboprop engines manufactured after January 1, 1995, or any PT6 series engines that have had their compressor bleed-off valve (BOV) changed after January 1, 1995, and which are installed in single-engine aircraft including, but not limited to the following aircraft: Air Tractor AT, Ayres Turbo Thrush Commander, Cessna 208 Caravan, Argo Aircraft G169B, Embraer EMB-312 Tucano, Frakes AF-CAT, Pilatus PC-6, PC-7, PC-9, and PC-12, Schweitzer AG-CAT, Aerospatiale Socata TBM-700, and Raytheon (Beech) T-34C. Note 1: This airworthiness directive (AD) applies to each engine identified in the preceding applicability provision, regardless of whether it has been modified, altered, or repaired in the area subject to the requirements of this AD. For engines that have been modified, altered, or repaired so that the performance of the requirements of this AD isaffected, the owner/operator must request approval for an alternative method of compliance in accordance with paragraph (e) of this AD. The request should include an assessment of the effect of the modification, alteration, or repair on the unsafe condition addressed by this AD; and, if the unsafe condition has not been eliminated, the request should include specific proposed actions to address it. Compliance: Required as indicated, unless accomplished previously. To prevent engine power reduction due to malfunction of the compressor BOV, which could result in a forced landing and loss of the aircraft, accomplish the following: (a) Within 100 hours time in service (TIS) after the effective date of this AD, but no later than April 2, 1997, perform a visual inspection of compressor BOVs to determine if the affected supplier's code number (No.) 8070, is on the cover, in accordance with the following PWC Service Bulletins (SBs), as applicable: 14251, Revision 1, dated December 2, 1996; 13287, Revision 1, dated December 2, 1996; 12134, Revision 1, dated December 2, 1996; 4204, dated December 10, 1996, Original; 3344, Revision 1, dated December 3, 1996; and 1538, Revision 3, dated December 2, 1996. (b) No further action is required if code No. 8070 is not on the cover of the compressor BOV, or if the compressor BOV has been marked with the reidentification "RE71" adjacent to the part number. (c) For compressor BOVs with code No. 8070 and no reidentification "RE71" marking, prior to further flight remove and inspect the cotter pin for any wear indications and inspect the guide shaft pin for any movement in accordance with the applicable SB listed in paragraph (a) of this AD. (1) If the cotter pin or guide shaft pin is not acceptable in accordance with the applicable SB listed in paragraph (a) of this AD, prior to further flight, modify the compressor BOV in accordance with the applicable SB listed in paragraph (a) of this AD, or replace itwith a serviceable part. (2) If the cotter pin and the guide shaft pin are acceptable in accordance with the applicable SB listed in paragraph (a) of this AD, prior to further flight, replace the cotter pin with a serviceable part. (d) Assemble and install the compressor bleed valve cover assembly on the housing assembly and reidentify the bleed valve assembly with "RE71" in accordance with the applicable SB listed in paragraph (a) of this AD. (e) An alternative method of compliance or adjustment of the compliance time that provides an acceptable level of safety may be used if approved by the Manager, Engine Certification Office. The request should be forwarded through an appropriate FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager, Certification Office. Note 2: Information concerning the existence of approved alternative methods of compliance with this airworthiness directive, if any, may be obtained from the Engine Certification Office. (f) Special flight permits may be issued in accordance with sections 21.197 and 21.199 of the Federal Aviation Regulations (14 CFR 21.197 and 21.199) to operate the aircraft to a location where the requirements of this AD can be accomplished. (g) The actions required by this AD shall be accomplished in accordance with the following PWC SBs: Document No. Pages Revision Date 14251 1-9 1 December 2, 1996 Total pages: 9. 13287 1-11 1 December 2, 1996 Total pages: 11. 12134 1-8 1 December 2, 1996 Total pages: 8. 4204 1-11 Original December 10, 1996 Total pages: 11. 3344 1-11 1 December 3, 1996 Total pages: 11. 1538 1-9 3 December 2, 1996 Total pages: 9 This incorporation by reference was approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies may be obtained from Pratt & Whitney Canada, 1000 Marie-Victorin, Longueuil, Quebec, Canada J4G 1A1; telephone (514) 677-9411, fax (514) 647-3620. Copies may be inspected at the FAA, New England Region, Office of the Assistant Chief Counsel, 12 New England Executive Park, Burlington, MA; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC. (h) This amendment becomes effective on March 14, 1997.